Lance Stroll says doctors actually cleared him to race a week ago in Singapore.
The Canadian, who ultimately sat out the race feeling unwell, revealed that his huge qualifying crash last Saturday topped the scales at 50G.
"Waking up on the Sunday morning wasn’t a nice feeling," Aston Martin’s Stroll, the son of team owner Lawrence Stroll, said at Suzuka.
"My whole body felt like it had been put through the wringer. Yes I was cleared by the doctors, but I didn’t feel capable of doing the most physically demanding race of the year in that condition."
That is despite the fact that he was checked for potential concussion, with Stroll revealing that doctors told him: "See how you feel and decide on Sunday morning.
"It was my plan to race if I had felt better, but I thought it would be better to recover completely and then get fit again in Japan than to force something. Driving in Singapore just didn’t feel right," Stroll explained.